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the VOYAGe
Hayabusa’s voyage started on 9 May 2003 when it was launched from the
Kagoshima Space Center (now known as the Uchinoura Space Center).
The spacecraft’s main engines are four ion engines with the acceleration
power as weak as a sigh, but with excellent fuel efficiency. The ion engines
worked near-continuously for two years, slowly propelling the spacecraft
toward its rendezvous with the Itokawa asteroid in mid-September 2005.
On the way, Hayabusa also experienced a gravity assist from Earth.
Hayabusa surveyed the asteroid surface from a distance of about 20 km,
before carefully approaching the surface for the collection of samples. This
was a critical moment for the mission because the long communication
delay prohibited Earth-based real-time commanding and Hayabusa had to
utilize its own autonomous navigation capabilities.
On 20 November 2005, the first attempt was made to land. However,
a sensor detected an obstacle during the autonomous navigation,
destabilizing Hayabusa’s attitude. After bounding bouncing a few times on
the surface, Hayabusa finally landed, and sat at a leaning attitude for about
30 minutes. Six days later the second landing operation was successful
as planned. However, it was revealed that no pellets to crash the surface
had been fired, but there was a probability that some dust may have been
kicked up into the sampling horn by the landing impacts.
After that, Hayabusa experienced a number of problems. A series of
communication glitches led to the control center losing all contact with
Hayabusa for six long weeks, and would eventually add three extra years to
the journey home. On the way, all but one of the four ion engines would fail
and the team had to rig parts of two of the failed engines to work together
and act as a single engine.
Through all these mishaps the scientists and engineers in the team worked
together to find creative solutions that allowed the mission to continue. On
13 June 2010, Hayabusa finally made it home - complete with its precious
cargo - ending one of the most spectacular voyages in the history of space
exploration.
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